An omni wheel includes a center wheel and a plurality of peripheral wheels distributed in a circular array with respect to an axis of the center wheel. The peripheral wheels can be autorotated (rotate along an axis thereof), and an angle (any angle except 90 DEG) is formed between the axis of the peripheral wheel and the center wheel.
A known motion device includes four omni wheels. The power generated by the four omni wheels can be finally combined into a composite force in any desired direction by control of rotation direction and rotation speed of each of the four omni wheels, so that the motion device can move towards the direction of the final composite force. The motion device can achieve a braking effect by increasing a resistance of the center wheel of the omni wheel during the rotation of the center wheel.
However, uncontrolled motion may occur due to other reasons in the braking process of the motion device, which results in poor braking performance.